Circuit controller



Sept. 5, 1950 R. B. HUNTER EQTAL CIRCUIT CONTROLLER 4 Sheets-Sheet 1 Filed Dec. 4, 1944 a a0 55 75 7o 59 59 59 1 R. B. HUNTER EI'AL 2,521,519

Sept. 5, 1950 CIRCUIT CONTROLLER 4 Sheets-Sheet 2 Filed Dec. 4, 1944 Sept 5 1195@ R. B. HUNTER EFAL CIRCUIT CONTROLLER 4- Sheets-Sheet 3 Filed Dec 4, 1944 USE I l 50 3/ I7 Z0 $375550 /4 50 p 5, 195 R. B. HUNTER HAL 2,521,519

CIRCUIT CONTROLLER Filed Dec. 4, 1944 v 4 SheetsSheet 4 SPEED ZAND 4 5PEED#1AND 5 M was 63% mm; mm

Patented Sept. 950

2 Richard B; I shorewood, L

i Mekelb ra' M wau W tion of -l)elaware it harem L.

Application December 4, 1944, serial No; 566,463

- 25'Claiins. 1

, This invention"relatestoimprovementsihpirtranslating devices and is particularly applicable tomn s of e ru ape. ,s

idesiable rrn of drum controller comprises switches biased to certain positi ns-andoperabIe against said bias by oscillatabl e cams carried by and operable through the medium of a shaft.

I'hee m 6f sw tq a e u ed p u e var e withthe circuit commutations desired, andthe lfo rrn and number of cams likewise .vary with .re-

quirements. In-s ornejinstances the switches are ;.requ'iredf.to;mal e and-break the main circuit ,of the controlled motor or other translating device p a d yetitisimportantc'ommerciallyto-make such 7 drums of small dimensions. ,ZAlsOflsuch drums must meet other exacting requirements.

, The present invention has "among itsio'bjects to provide an improveddrum of the character aforee stated which-Will have better operating character- :istics-and greater" flexibility for diff'erent uses than those heretobeforei.available. 1

--.;1Another' object isltd provide such'a drumof sin-ip1e;fs mall andfconipact form jp'ermittin'g of a' s'ubi withoutcchange in overall dimensions.

stantialyatisttion in number of switches employed 1"Aiiother Object is m provide a 'drumstriifcture rendering the switch contacts easily andfduickly accessible for inspection; repair andrepla'cemerits. I i "Anotheifi object is to provide for mounting and -demounting the switches in groups; and fo'r incorporating the stationary contacts of all switches of agr ou'p in oneself-containedassemblyand all movable contacts of the same group of switches :in-a second self-contained assembly which ass'emblies' may beq'uickly and easily mounted in coasting relation and as easily removed for inspection and replacement of contacts. 1

Another object is to provide a drum having the characteristic" of" making a desired circuit com-- m-utation only after movement of an operating handle to anoverthrow'position and *partial return thereof, with an indicating dial which directs proper manipulation for the desired circuit achanges without ':confiision' of the" user by the aforementioned operating characteristic of the drum, and without needof the user 'evenknowing the -'afor'ementioned operating 'charat'eristic;v

:-Another object is to provide forsuch drums a camoperated:switching means advantageous in saving space and in bther respectsftocontrolan.

ae'lectrornagn-etic main swit'ch for low onagep .tection and so called intermediate point pickiip. hno'therlobject is to provide adrii'm constructionicadvantageous forwarious' applications and 'fpa'rticularly for multispeed alternating current 'motors.' v

V gvmfous other objects andladvantages of the invention will hereinafter appeanf Anembodiment of the invention is illustrated infth'e accompanying drawingswhich will now be ter d ibing nd rs t't em o kment illustrated is susceptible of various modifications" without departing from the scope of the tr h if aiin v. in the drawings, v el shdwl Ia e clo ed d um. tr l casing and parts, of its mechanism shown i fi n;.-.e.1. H a o Fig. is a transverse sectional viewof the drum niecha' ,sm .on ,l inej2 -2,-Fig. 1; V

a detail view ofa cam', of Figs. 1 and 2; v Fig. fi shbws partly in elevation but mainly in section part of the shaft andcam assembly of Fig.

l it esee iqnin bein a n'ali 4- M Fig.5 is a 'sectionalview on line 55, Fig. 1;, Fig.6isa transversesectional' view of the drum 1m? anim Q f ee6.: Fi LY a is, bdttorn plan view ofthe taperedsec- 'tionof one ofthe switch-blocks of Fig. 6;

Fig. 8 is at p plan view of the switch block jhoiw 5 I Fig. 19, a bottom planview of the uppersec- 5 I a th 09 iF a Fig.10 is a fragmenta ry View on line l0l0,

- Fig. 8, ofmone of the switch blocks together with one of the contacts to be mounted thereon;

Fig.1 11' shot/s one set of switch contacts provi'dedwitha wear measuring" device; v I

Fig. 12 .i hflelevational iew 011 a reduced s', 1e ofjt'he operating handle and dial shown in s siiemat e ans in trim ed view .t'rdl'ofa mu1tispeedA.Q.mtor. H p p 4 p to Figs. land 2,1'the drum comprises five' switch blocks l arranged contiguous to anew/n 1 a rotatable shaft 2 and havin i ""w'ith' sa'idfshaft including fled isuch'elements bein .3- .fr olr nf'which the V I ion by handle I}. The f gf3which inay. e "of 'anyprefei red form ha'istheiein 'in' relation therewith 'ajf rarne comprising a members 5' nd s' respectively party ng? b arin'gs Tana sfjror western idjre- "spgecnve" 37f ear and feta whichthe e mo; 'sivitch ioclgsiar seouredflAsslflown om one anothe except 'the case of of'the drurn controllerillustrated,

"theextremd ears of the series: Theother frame The switch blocks preferably extend substan tially the full length of the shaft within-the housing to carry a plurality of switches, and

preferably each is of the cross sectional form shown in Fig. 2, each being narrow and tapering in approach to the shaft 2 whereby said blocks may be closely assembled in an are about said shaft.

I whichledges must of course be so formed as to permit the contact tips of contacts H to engage contacts |3 before and after surface wear of the cooperating contact surfaces. The construction shown is such that while the ledges 28 prevent accidental releaseof'the contacts l4 from the block section I under'the pressure of springs 24 it is possible by tilting the contacts sidewise to provide for withdrawal thereof from the block section I at will. Thus such self-contained assemblymay be assembled and disassembled quickly and easily by'mere manipulation of the parts I thereof without need of tools. The block section The switches carried by the blocks are of like construction and are preferably of the I double break type, each as shown in Fig. 2 com prising a pair of stationary contacts I3 and a bridging contact I4, 'the'stationary contacts l3 having extensions affording wiringterminals l5 external of the block; Each switch block comprises two separable sections, the tapered or base section to be referred toby the block reference numeral I, andthe second or upper section being designated as l. The section I has its upper side channeled longitudinally, as shown in Figi 8,

for seating therein a plurality of pairs of the aforementioned stationary contacts [3 and for receiving the upper block section l b The upper bl'ocksectiorr l as'shown' in Fig. 9, has'notchcs l1 -therein to receive with close fit the shanks of contacts l3 and to permit said section l tofit snuglyagainstthese'ction l, and section I has separate open recesses'or chambers overlying the several pairs of contacts l 3 's'aid'- chambers or recesses accommodating the severalbridging contacts M-"and guiding the-latter in their movement relative to their respective-stationary contacts l3.

The contact receiving recesses or chambers of block section l may beopen only on'the face of said section bearing on block s'ection 'l, or'may also be .open on the-opposite side of section I,

"except for ribs it, as shown in Figs. 2 and6. In

either case the section i provides for each set of switchiconta-cts; to-witfa pair of contacts l3" and a bridging contact l4,'a four-sided continuous -wall encircling said contacts while the section I f 1 forms an endwall when the block sections are assembled. As shown in Fig. 9, the bridging contacts |4 comprise oblong plates having at adjacent opposite ends contact tips 20, said plate having intermediate laterally projecting lugs 2| 9? -while the block section I hasits' recesse's' so formed as to provide inopposed wallsj thereof slots 22 to receive the lugs H to guide'the7G'O ltacts M in their movement perpendicularly or I has at opposite ends slots to receive mounting bolts, and preferably said block section has through conductor slots 3| located between adjacent switch receiving recesses or chambers. In the-particular block section shown in Fig. 9 there is a recess or slot 32 connecting the last two switch receiving chambers at the left hand end of'the 'blockto enable electrical connection of the bridging contacts of such chambers for purposes hereinafter-set forth, the electrical connecnection-being made as shown in Fig. 1 by a pigtail 33 in slot32.

' The block section I, as aforestated, has the plungers 25- reciprocably mounted therein, and

referring to Fig. 8 it willbeiseen that such plungers are in cross section oblong, being in length and-*width likethat 'transvei-se part of contacts H comprising the oppositely projecting lugs 2|. Accordingly as the plungers are positions in block l to register with said partsof contacts l4 said the stationary contacts l3. Coilsprings 2 4: seated in the ribs I8 of block section I bear upon 'the contacts l4 centrally thereof to bias themto', engage their respective contacts I3 while plungers 25 reciprocably mounted in the other blocksec- M tion I engage contacts [4 centrallythereofand afford means by which contacts I 4 may bejindividually moved againstthe bias of'their springs 'for disengagement from contacts I3." Each block section I together with the contacts .l,4,, and

springs 24 therein preferably constitute a self' contained assembly and to thisend the. contacts [4 are locked against displacement from block section I. As shown in Fig. 9, this is accomplished by providing each contact [4 adjacent its m opposite ends with oppositely projecting nibs 21 which overlie ledges 28 formed in block section plungers will when used to move the contacts,

enter and slide into the-guide slots 22 of block section I In so doing each plunger will subdivide the respective recesses or chambers in block section I into'separate and complete chambers for the two pairs of cooperating contact surfaces of the respective switch, thus isolating each of said pairs of cooperating surfaces. Moreover as willbe observed -,f rorngFigs. 2 and 9, the openings in block section, I through which the plungers project'areclosely fitted by said plungers and hence each switch. recess in block section I will remain substantially closed atone end by block section I Each plunger not only has a close fit with block section I adjacent the surfaceof the latter but it is otherwise guided in its movement.

As shown in Fig 1 which shows the broader sidesof the plunger 25, each plunger has laterally and downwardly projecting portions 35, the upper parts of whichtogether with ribs 36 (Figs. 1 and 2) extending along and projecting from the broader facesofthe plunger; afford the plunger a part in crosssection having at its four corners right anglenotches On theotherhandthe base section I has its receiving recesses formedto match sirch p arts of theplungerswith a close fit continuing throughout the operating range of movement of each plunger whereby theilatter is held .to a rectilinear path without possibility of appreciable lateral shiftingv or tilting. The projecting ;portions 35 of each plunger provide for the :the maselof 131181117011 1 plunger; of-tFig. 1 whichzhas ionlylonel side of5theefonkwengagingsthemod; lillhe .rod's 4itlhaslooselymountedlthereon-spacedmpllem e41. each .itoibfidin aligmnent-avithallplungertH, rclearlance therefor-being afiordedvbyrthei aioredescribed forked formation; of ithe-l ibase oft. leach plunger; flhe rollers-, ailvarerprovided. for tengage- 'ment. "with :they operatingdcams. hereinafter.Ls'et ,'.fQnth,,-.and as will-he; under-stood zarealiftecl bynthe to liitythe irod all]; the ,w-allsto'fi ithearecesses .,in.the hlock section llxadjacentsuch rollers being limcmed rtoaaifondisaid rollers the necessary clear.- ia ce. .vzlfilhileethe-, w.alls of block sectiond adjacent the rollers afford guides.;-.thenefor.andhence tor iil fitliQdLAm also, itis iprefenableeto indepen y Jenidclthe rollerslelliwherebylthey may bemelieved I hirpress re a a nstthemallshofttheablock section.

511151 may. he afifiO lpl hed yltpljoViding son. the it the smaller; craraterollersisz;Figs;..d and h m yobe-gcithertl oose :on [the-trod or fixed h are preferably; OZfifiimGHS-iQDS d ;;to be ellidedubyncertain vof sc ssesl-in hlcchsectionlliyvnich serizelalsolasimnns r; hide -p Thelength; ofwzthe nos; A n c e aflarl' iediflnd .inthe drum two refer blyllenetheneditozenset not l 53,33; iithez; lend shes ble ohavetheblocniseci- I nta nedassemblyand r h. cnta s are. secured :tosthe 9 515045 '1 cked..-against nr e d; to :J' llQ :block .Section 369i inurecesses -.in. .the hcynma he.attacnedandsmmtools. I e slot ed lmilgitudinally si cxten in hfrom. the con .3. .thmushout the l er-j Of the'ashank, as shown e n t shankmompress fi -5.5 1 6- .eAlso. the shank 10f eraply LQf increased width 0 Wgslgehinto azsli-ehtly nth-.

lologl; ectionj. Asshown a: front-Slater fn 2h8..- Q eSS,-;t0;-reoeive shank ,carryingnthe th ti angles he hank! recess. Preferably the ifidiii ct c ;b1OBkL;Sc1li0n I bygthe n' E '.-.6.iand.7. Thisgmeans P. is 5 ecured @gainstione. of .the e 1 hlock sectionand having set v11 ext nding across t euzactuatingcams,such: in 5 96k I,., :.Q QS. fs ctionvinylilig. .1. is pro.- Eigs. l Ie in swat hespm dedismio ksection I and ured therein by screws 53.;;g5[2he block.

out; e'ed ofilimitatiomoiaits I Preferably: the I li cndic lar K295151011; as I ,section ii'nhas .end' slotsi" ion attachment purposestandnnoztches -56 complementing the slots -31 in "the: block section la to':.complete"the wire passages aforementioned. Also the block section .-:i .has pins .55! and58 adjacent its DDDositez ends which fit in depressions in the section le, certain of the pins andthei-r respective depressions being of. greater diameter than the other pins and depressions to insure. against assembly of the vblocle sections except in the right relation.

. As shownin Fig. 1, theblock sections are'attached-to their supporting-ears by bolts 59 preferablylprovided with nutszfiil and 59- to afford securementof the block sections --individuall-y whereby thesections H may, if .desired, be re- .moved Withoutloosening the block sections 1.

"arenonwotatahle on thcshaft Referring .to Fig. L me-shaft 2 preferably is'of -polygonalcross-section and as shown car-ries- -two 'like pairs .ofcams.t95j to coact with the two rollers AH, and an additional cam fl-Q for-the purposeshereinafterset forth. Thecan'ls {6t and lfi with polygonal central openings with which the shafthas a close fit; whereas-the eams fi-i "are rotatablymounted on said shaft- Both cams -fiil are of the form clearly shown-in Fig. 2,-each having therein a slot '62, whereas-both cams 'iitare of the form 'bestshownin Fig. 3, eachhaving a vpin t3 projectingperpendicularly from oneface thereof and an orifice 5 in assembling the passed progressively through theor-l-fice- M in the "oth'enc'am filLand the slot-6'2 in the cam tfl'adjacent the latter. cam 6.4; as best shown in Fig. 4.

Consequently the coaction of the cams of-"both sets willlrbeithe same, with the same lost nzotion connection between each pairofcams-fii! and fil,

. and thus. it :.willbe apparent that the two sets of cams acting through the rollers 4| will lift the rodor-rods lw and allow it .orthem tofall wi-tl:1

outtilting thereof, to control uniformly all sWitches of each-block subjected to the influence of said'carns. The two sets oicamstfl-tl and.- the-cam' 10 are retainedin "proper positions on the shaft axially of said shaf-t as bythe customary- L tubUlar Spac erS out" to the desired length and slipped acnto theshaft sequentially with the cams .in r'naking'the: assembly. "The shaft 2 'issho'wn as iiotatahly mou ntcdsina conventional manner andlasahaving-,the handle l' fixed theretoin a V e these details will notice lzhown': waywheref ed, it being-Bnndcrstood that the shaft may be rotatablysup-ported in any preferred wayand that the handie r lely bc secured to l the shaft in I I e'respe'cti-vcly provided with relatively dc'ep no 'oaim has other peri-ph'e'ral" notches-said 'cains hrough coaction with th'e rol-lerst 4 I raise eel-ch of the rods 4 0- -for opening all switches under the influence-thereof ih all rotar positionsof said cams except as the pal-rs of rollers are permitted motion by aligi-"lm ent therewith of the relatively de'e-pwtches-of both cams. Then the'switches influenced Lhy'th rodscarrying such rollers are allowed-toclcse under their hiaswhile'al1other switcheswhich-are under theinfluence-ofthe Teams-are" held'open, and as the cams move on athey immediatelyeffect op'eningof =the closed switchoraswitches byforcing-their respective arlollerscnnto the ihigher portions of the cams. :Moneovermhenfthe cams 6ll-'-5 l' occupy a relation iin: whichiithesnctchesa 155.1 andmfi Siare in registry 11he1TJ1Gg31rdlfilSSJ0f tnexrotarymosition of the oams cinitialifmovem ent sof shaft: impartslmotion to -provided assure the cams 60 but not to the cams 6| until the lost motion between cams 60 and 6| is taken up. Meanwhile the notches 65 have been moved out -.of registry with the notches 66, and hence continued rotation of the cams will not permit closing i ming action of the rollers 4| under the influence.

of the biasing means of the switches about to close. Such return movement of the shaft will also be assisted by the camming action of the other rollers in entering the shallower notches of the cams. Here it is to ,be noted that as shown in Fig. 2, when the notches 65 and 66 are out of alignment with all rollers 4|, all rollers 4| enter the shallower notches in said cams, the shallower notches being spaced to align with a multiplicity of said rollers in all operative positions of the.

drum. Thus the rollers 4| in coaction withthe shallower notches of the cams afford star-wheel action for defining the operative and the off positions of the drum and at the same tim insure registry of the notches 65 and 66 in the off position of the drum, thereby centering the pins 63 of cams 6| in the slots 62 of cams 66 and assisting as aforestated in bringing about the same relationship of the cam in each operative position of the drum. Such control of the switches through cams having lost motion affords closure of the switches of the several blocks either in a natural sequence or in any other desired order, always requiring for closure of any group of switches rotation of the shaft first in one direction and then in a reverse direction. Consequently the usual form of indi eating dial is not well suited to suchaidru'm.

However, the indicating means now to .be de scribed is wellsuited to such drums.

The indicating means illustratedcomprises .a

dial 15 shown in section in Fig. l andin elevation in Fig. 12, this dial bearing the usualmarklngs.

The dial 75 instead of being fixed tothe drum housing has a bearing 76 on a part fixed to the shaft 2 to permit rotar movement of the dial relative to said shaft. On the other hand, the dial 15 has its rotary motion limited bya stop 17 provided on the drum housing, .which projects into a wide notch 18 provided inthe dial.

peripherally thereof.- Moreover, the dial has bearin 'against the same interiorly thereof a spring friction disc 79 carried by the shaft 2 and fixed thereto to rotate therewith. Accordingly the dial 15 always tends to rotate with the shaft but slips thereon when it is arrested by engagement of either end wall of its notch 18 with the fixedstop ll. As shown in Fig, 12, the stop 11 in off position of the drum occupies a center position in the notch 18, and assuming the, handle i to'be moved clockwise to any of its running positions as, for example, position 2, the dial moves with the shaft through an angle equal to the lost motion between the cams 60 and 6|, incident to the circuit communtation to be effected. Accordingly the handle in order to be brought into registry with the numeral 2 on the dial must be moved to the overthrow position required for the desired circuit commutation. Then when th'e handle moves counterclockwise as anincldent'to its mg "84 from engagement completing theselected circuit commutation the dial moves counterclockwise with the handle to .theposition of rest of the handle. The dial thus indicates in therusual manner the position of the.

drum. Meanwhile the relationship of the notch inth'edial' and the stop 11' is restored to that shown in Fig. '12, and hence the dial'will serve in ithe'same manner to indicate the necessary movement of thehandle for any'further functional movement of the :drum and to indicate properly the position of the drum when the-handle comes to rest, whether the handle be moved clockwise to posit'ion 3 or position 4, or counterclockwise switches whichfor reference purposes will be designated as lAand -B; respectively, are of the same 'constructionas the other switches, but switch A has a shorterplunger thanthe switch B. for

purposes hereinafter set forth. Switches A and "B have individual cam engaging rollers and 8 I, respectively, mounted as shown in Fig. 7, whichit will be assumed shows the block of switch A hav-' ing roller 80. Roller 8|] is shown'in Fig,f7*as mounted on a short rod 82 having fixed'thereto a collar 83 on one side of roller, 80 and one of the smaller loose rollers '42 on the other side of roller 80,-.the collar :63 and roller flbeing'of like "dimensions and the roll'er being of the same d mensions asthe roller 4| whereby the single roller assemblieswill --fit theplunger receiving recesses in block I, as in the case of rollers 4| and "their associated rollers 42. As aforeindicated both rollers 80 and 8| are in a coplanar relation with one anotherand-with the camlll which in theposition shown in- Fig; 6 has its peripheral lug-8| in while having its concentriclow peripheral surface BS'in registr-y with the roller 8| to permit switch 'B-to close, -said cam also having a concentric high peripheral surface 81. Such position of) the'cam'|8 corresponds'ito the'off position of the drum and 'asthedrumis moved clockwise the cam zlflmovs' in-the same direction to withdraw with roller 80 which :drops' ontothe high concentric surface 61 of said cam. Switch 'A 'isthereb'y permitted to close due to the shortness of its plunger, and meanwhile KsWitch B has remained closed. However, as the drum 'goeslinto its first operative position the lug 84 of cam 10 engages andlifts roller 8| to open switch B, but -as'will beapparent thereis an in; ltermed'iate" positionof the "cam 16 where both switches'are closed; flAfter-switch A is closed and switch B is .opened continued clockwise rotation 'of camu'lo permits the roller 8'l-to drop on to the highconcentric surface 8'! of the cam, but owing to the' length of the plunger switch is not permitted to close. Accordingly throughout continued clockwise movement '01 the cam, 10 within, a total range of one revolution the "switch A remains closed-while the switch B remains open. "Then upon return of the drum to'ofi position from any'operative position, switch Bis heldopen until the cam 10' reaches a position in- "'termediate the first operative position of the drum of switch 3 said i s sal-55 m to' an'd through the ppra ti'ng' winding of switch 90 150 line' L Then' whe'rrswiteh iBis opened' continned energization of the Windlfig'Qf' switch 90 is rendereddependeritupon=the cireuit-"fromline L -'t0"a-nd throughswitch "A to arid throughmora mally open auxiliary c0ntaCts"94 t*O- the winding ofs'aidswitch 202* Thus if there baa 'failiire pf voItageyswitch \lll willepen and remain openum' finders teed sthat ii here mer e nrotidris-of the control shaft-"Tor effe'cting circuiti commutations becomes unnecessarythefirclixiaryfindieatirig dial i may be substithted -fof the" 'di'a31- shownand described; *bOt-h seems scribed? and that'the switches fpr control' -efthe main switch" may "be differently incOrpOrated thedri m whe'ndt is mindf-advaritag'eousto do: sq;

1 contacts! Prefelablywhesections l and the til tl'ieldrum isriibVedtba positibiiintermedi'ate the first eperative positibn and the off positio'ir td=releaseswitcli B'='fof recl'bsure, whereas if the" switchesof five e'aclr and iis'e ofall' such switches; 1..

this-schematic sliew'ih depit' thefcharaetristic Witches A and ?B irra ceplanar re v anbth'erand the'emi; switches-fi th other twb sets' ofswitelres:

tfowig: 13 vvfncrrfor centra thus exempliffyfng saving" in ength "oftheforsueh coplanar relatmnshipwf shh switehes:

Also this diagram exemplifies the utility 1 of the" afbredeseriljed electricalennectiens df eertaih' only bne of vari uspossib1e-uses= of drums OfEthe cha'ra'cter set forth; as the diai-gr'amis self explanatory-it same in detail! As wur pear's needless v qdescrib'e the 'e und e'rsto'ecl frem we description of he drum mechanism? inoi ementof the drumt0 mentary clbsure" df-"sWit'cT-i A for energizatibnor main" switeh= 98 Tl-1e remaining switches ofsaidt row b' estamlsh ctmnectienslfer the right hand-set of primary windings of motor-M for a first speed? Miivement 'ef the drulm to" its second ioperative positi eir opens all" of tl i'e switches--=of r'ovv I ex -j Cepfi-switeh-A amdcl'eses all'bf'tIIe SWitGhBS-Of row 2" 'xcepfiswitcll B) which has been opened and remainsopen; as :earIier eXplai'ned.-= Closure-0f the switches of row? establishesconnections-fer the le'ft hand" set ef the-motor primaryswinclingszfof a; seeond -speed Movement of"the-drum to third"operativespositien opeps-allelbsed switches ofrows 2' and closes all switcl ies of rim '3 to establisfi conneetiens for the right'hand set of motor primary windings *for' a third-speed; f Movement: of thei'drum its fourtl n operative positi'onlopens all switches of row 3 and closes allsw-itches ofr ow 4- t'b: establish Gonneetions for the left handset-0f motorprimarywimiirigs-fer'afbm tlr-speedit As's'will' he 1 .untlerstoed): the dbuble cam econtrol ofi lth-ez motorcircuit-switches may be dispensed wit-m where; unnecessary, and: the. drum :may' b'e" varied bmt'bl a's= to:the'inumber of'switch black-sand themmnber-coil switches 'iis;eaeli-.c' blerclsraecordingz to: Jthez:circiuitsctucbe::eentrolledi Alsd it; wmwev 1 may be provided with-sum 21 'WHatwe claim asn'eW e reverserdirie'ctibmii" I contacts 'ai'efl fermed 'ofsome of'the'known silver compoundstdfipinimizeareingb v, v Referring t6 Fig' 1 1 the eontatwear indicator shown therein 'compri'sfes a pin95 reciprocable in arr ope *g prov'ided i tl're rib lfdf theswitcli bleak sectl-on I isaid pur-iaassing axiallythrbugh the Spring 24' and threading 'ii'itb thQ contact- 14} to" be 'abtach ed theretci af- -said I boiltabt-"is mountedin .the blec'kf "sectien As wil'l be 'aphence its degree 'of brojectmn rro'mthe rib I 8 with the "switch" closed will afidrd indicationof 95, and as Will be apparent t released frdnith eeritaets Letters Patent is l fln a drum y I binationsja frame, a 'sha-ft retatably supported therebyifa plurality otiswitches-supportedf by said fizames'in. rows disposedlinz an aridia'boiit said shaft, and? operating'ecjonneetioris between s'aicl switches andssaidzshaf t whieheoinprise c'ams on said shaft; sa-iebv cams E affording througlrithe-i medium' of saiicl shaft shy-rotary moviem'lents-:-thereof ciperations of; saitl switehesrow: byzrowvinenatusal sequence or: selectively regardless of such sequencer w Q2wI-n a, dr-um type circuit-controller, in-combination a z firame v a shaft rotatably supportedr thereby; a: pluralityofisWitChes-Supported. byisaid frame in rews disposed in: anw'arc' about said shaft;

3. In a: drum: type circuit controller; I in co in binatiom' a frame; shaft rotatably supborted therebmza' pluralityflof switches supported b'i said ual toJdiffierentgrdups of saicl switches, saitl ele ments'being' dispesed-im mamabo'ut sai'di's'h'aft, and'c'ams on sailtr'sfiatt affording through the mediumsof .eaid' 'shaft'lfiy rotary mbvement's were offiopenatieiis'i ofii 'said 'el'ements i-r ia natural sle;

11 elements being disposed in an arc about said shaft, and cams on said shaft affordingthrough the medium of said shaft by rotaryrnovements thereof, operations of said elements in a natural sequence or selectively regardless of ,such sequence, and said cams comprising coacting parts interconnected for limitedprelative -rotary;.play such that for the aforementionedoperation -o f any one' pf said elements said shaftmus ba bi fid to rotary movement first in one direction, and thenrto alesserdegree in a reverse direction.

-5. In a drum type, circuit controller, in combination, a frame, a shaft rotatably. supported thereby, a plurality of switches supported by said frame, a, plurality of, actuating elements individ-, ual to different groups of said switches, said elements being disposedin'an are about said shaft, and-cams on said shaft aifording through the medium of said shaft byrotary movcments.;there-, of; operations of said elements in;a-ri atural se-; quenceor selectively regardlessof such sequence, and said-cams comprising coacting'parts inter; connected for limited'relative rotary-playsuch that for; the aforementioned operation of any one of, said elements said shaft must be subjected-to rotary movement first in onedirection, and then to alesser degree-in, areverse direction, saidlele-T ments being biased to bear against saidacam parts andto coact therewith' toeffect-automatia cally the aforementioned. lesser :reverseuanovementsof saidlshaftn r .6. In a drum-type circuit, controlle -lin (30111111 nation a frame, a shaft -rotatably-supported thereby, a plurality of s gvitcheshaving individual plungers for actuation thereof, said yswitches being supported by said frame in rows disposer-lain an; are about: said shaft and bBiDgSO' supported with their plungersextending toward-said shaft in a radial relation thereto, and cam operating means for said switches associatedwith' said shaft for'actuation of said switches by rotation of said shaft, each of said rows of switches beingcarriedby'a supporting block removably attached to said' frame and having attaching means which are readih accessible and'which' enable its removal individually. 1

7; In a drum type circuit controller, in co bs nation, a frame, a shaft rotatably supported thereby, a plurality of switches having individual plungers for actuation thereof, said'switche's being supported by said frame in rows disposed in an are about said shaft and being so supported with their 'plunge'rs extending toward said-shaftin a radial relation thereto, and cam operating means for said switches associated with said shaft for actuation of said switches by rotationof"sa'id shaft,feach of said rows of switches being carried bya supporting block removably attachedto said frame; and having attaching means which are readily accessible and which enable its removal individually, said switch supporting blocks at -least in part being in cross section of tapered form for compact assembly about said shaft.

8. In a drum type circuit controller, in combination, a frame, a shaft rotatably supported by said frame, a plurality of switches having individual actuating elements, said switches being-supported by said frame in rows disposed in an are about said shaft, cams carriedby saidqshaft andthrough the medium of which said switches are operable by rotary movement of'said-shaft, and means by which certain of said cams are, madean actuating medium foraplurality of switches of a single row, such'plurality exceedingin number the number of cams acting thereon.

9,; FIn a drum, type ,circuit controller, in combi nation,: a frame, a shaft rotatably -& supported thereby,- a plurality of switches having individual actuating elements, said switches being supported bylzsaid frame in rows. disposed in an are about said shaft, and carnsr carried; by .said shaft ,and throughsthe mediiun of ,which saidv switches! are operableby rotarymovement ofsaid shaftyeach of, certain aofsaid rows of switches havingassoelated therewith a'comn on actuating'element for a group, of the switches thereof, which common actuating element is operatively associated with certainofsaid cams; w y a w :21; ,;,10.--,-In a drum type-circuit controller,--in comj-. bination, a frame,-a shaft rotatably supported thereby, a .plurality of switches-having individual actuatinge1ements, said switches being supported by -said frame in rows disposed in an arc about, said shaft, and cams carried by said =shaft andzithrou'gh the medium of which saidswitches are operable by rotary movement-of said shaft,

certain;ofytheswitches of a single row having thereby, ,-a;switc h, blocksupported bysaidirame;

in spaced relation to said shaft, said, block comprising a section -having at its-outer sidean open recess,;-and,comprising a. second section seating in the, open recess of said first section, stationary contacts seatedin the recess in said first section.

to lie within, a, central recess of said second sec-l tion and-having: exposed wiring terminals, as bridgingxcontact movablymounted in said-sec? Qnd sectionandhaving a biasing spring urging.

.A it to engage said stationary contacts, a plunger:

reciprocably mounted. in said first section and engaging said bridging contact, and means ineluding a, cam on said shaft to'engageand oper ate; saidplunger to disengage said bridgingcon tact from said stationarycontacts.-- 12., In a -drum,type circuit controller, ,in bination, a framepa shaft rotatably supported; thereby, a switch block supported by said frame inspaced-relation to said shaft, said block com prisinga section having at its outerside on open recess, and comprising a. "second section seating; in the open recess of said first section, stationary. contactsseated-in the recess in said firstsection to lie within a central recess of said second sec-, tion and having exposed wiring terminals, a bridging icontact, movably mounted in said sec-- ond sectionand having a biasing spring urging it, :t-oengage said stationary. contacts, a plunger reciprocably'mounted in said :first section and engaging said bridging contact, and means in-l. eluding a cam on said shaft'to engage andcperate said plunger to disengage said bridging contact from said-stationary contacts, said block together with said plunger providing forthe pairs, of cooperating surfaces of said contacts separate insulatingchambersl I 13.,In a drum: type circuit controller, in com--' vbination a frame, a shaft rotatably supported:

ass gns together with said plungerproviding for the pairs of cooperating surfaces of said contactsseparate insulating chambers, and said second blocl; section and said'plunger comprisingmelamine resin:

1l4. In-=a drum type circuit controller, in combination; a frame, a shaft rotatable? supported thereby,l-aswitch block supported by said frame in spaced relation to saidshaft, said block comprising a section ha-ving-atits outer side an open recess-and said block comprising asecond sectionseating in the open recess of said first sec;- tionp stationary contacts seatedinthe recess in saidvfirst- SCOlJlOIl -H) lie withinxa central recess of said secondisectionand" having exposed wiring terminals, abridging contact,movably mounted insaidsecondsectionland having abiasing spring urging it to engagesaid stationary 'contacts-,--a: plunger reci-procably; mounted in said-first: sectiomand engaging said bridgin c contact, and means including a; cam-on said shaft toengage and-operate saidzplunger to disengage said bridg ing-z contact (from said stationary: contacts, saidblocla together with" said :plumger providing. for

the pairs-of cooperating r surfaces? of said con tacts separate insulating chambers, andl'said sec ond sectionof saidiblock together-'- with said bridging: contact and itsbiasingspring consti tuting i a self-contained; assembly removable from said frame independently ofcsaid first: section of saidblock. I

lids-Ina drum type circuit controller, in com-- bin'ation a frame,- a shaft rotatably-supported thereby, a switch block or oblong form supported-- tion= suchteas :"to bring. :the several pair's! in line.

with-recesses in said second bloclesection, a pluralityfof bridging contacts movalolymounted in different recesses in'isaid secondblocksection andueachahavinga bias-mgsp-ring urging it to engage aypair of said stationary contacts, a plu ra1ity= 'of plungers reciprocably mounted in said.

first :b-locknsectionpeachto engage one of said bridging; contacts, I and. means? including camson: said: shaftto engage and operate said plungers to move said bridging. contacts against" said bias,- sa-id block" together withsaid plu-ngers providing; for eachapai-r of cooperatingsurfaces of said con tacts aseparate insulating :chamber.-,

- 1-7; Ina drum. type circui-tcontrol'ler, in com,-

bination, ;-a frame; a. shaftrotatably' supported thereby-,2 a= switch. block of oblong form supported by said frame 1 inspaced-and parallel relatiorrto said-1 shaft; said bloclc comprising a first'section having omits outer-side: alongitudinally extend-- ing: recessrandi comprising! a. second sectiorrseating: in 517118 2013911 recess.- of said first section; and

having a series of recesses aligned longitudinally of saidblock and. shaft, a plurality of pairs of stationarycontacts seating the recess in said first block-section in spaced relation such as to V bringthe" several pairs in line with recesses in by said frame in spaceda-nd parallelrela-tion to:

said shaft, said bloclclcomprisingi.aiirst section: having'onl its outer side a longitudinally extendin recess and comprising a second section seat: ing in tklGyQPBi'l' recess :of said first'section and: having a. series of recesses aligned longitu'dinally of said block and shaft, a plurality ofpairs-of stationary contacts seating in; thegrecess in said first blocls sectio-niin spaced elation such as to bring the several pairs line; with recesses? in: said i second block section; a plurality of bridging:

contacts mov-ably -mounted==in-diiferent recessesin said second: block section and? each having a biasing'sprin urging-it to engag-ey pair of said:

stationary contacts a plurality of'g-plunger's re'- ciprocably-lm'ounted in said first: block-*sectiom:

eacirlie-engage one: of said bridging;- contacts; and? means-including cams on: sai'd 's'haftito engagesaid sec'ondtloloclr section; a pluralityof bridg ing contactsmovablymounted in different-"ratacts and means: including cams onsaid shaft to engage and operate said plungers to move saidzbridging contacts againstsaid bias, said block together-with said plunger-s providing for 'e-ach pairof cooperating surfacesof saidcontacts a se ;raratr- -.'insulating v chamber, and said second block: section together with said bridging contactsand their-*springsconstituting a self-com tamed-assembly removable from said frame independently-of. said first block section.

i 18,2111 a: drum. type "circuit controller, in com lation tosaidshaft, said bl'ock: comprising. a first section having on-itsouter side a longitudinally extendingoperr'recess'and said block comprising a second section seating: in the-open recess of saidifi'rst section and having a series of recesses aligned. longitudinally of said block, a plurality of pairs of" stationary contacts seating in the recessin .said first blo'cksection in spaced re1a'- tiorrisuclr as to bring the several'pairs in line witrr'the'irecesses'in saidsecond block section, a

plurality of bridging: contacts movably mounted lay-said iramein spaced and.lparallel relation to said shaft, said block comprising afir st; section having on i ea w tu1lin tending recessfiandc'oinpr-ising 'a second section seating in the open recess of said first sece" tion and having a series of recesses alignedfil'ongitudinally of said block;zand:,;shait, a plurality of pairs; of stationary contactswseating in the recess-in said first block sectionr-im spacedrelae in diffierentreces'ses in said second block section and ea'ch havin'g a biasing spring urging it to engage'a p'airrof' said stationary contacts, a plurality -of 'plungers reciprooably mounted in said first: section-of said block, each to engage" one otrsaid bridging contact's,a'nd means including camswon'ssaid shaft to engage and operate said plungersto move-said: bridging contacts against thein s-pringibias;said: means further including a spindlezengagin'gia;v numberfof said contact-ac- I tuatingiplungersiand 'also engagingcertain of said cams'onsaid? shaft, 'saidlspindlerb'eing confined in saidefirst SQCtiO-IifiOf said block with fre-ed'on'r of movement thereirr to serve as an operatingmedium for said plungers'. v

- '19: A?smtchibloclc'rorrdrum controllers comprising a block of attenuated form dividd long i tudinally into a base section and atop section, the base section having a face thereoflongitudinally recessed for seating therein the top section, and the top section havingftherein in alignment longitudinally thereof a series of recesses, pairs of stationary contacts seated in -the recess of said base block section and having ex tensions extending between theblocksectionsto' ating faces of said contacts an insulatingchamber closed on all four sides and at least at one end.

20. A switch block for drum controllers mom:

prising a block. of attenuated form divided'lon gitudinally into a base section and a'top section;

the base section having a face thereof longitudinally recessed for seating therewith the top section, and the top section having therein in alignment longitudinally thereof series of-recesses, pairs of stationary contacts seated in the recess of said base block section and having extensions extending between the block sections to the outside of the blockand affording wiring terminals, said pairs of contacts being spaced for locating the same in different recesses in the top section, bridging contacts movably mounted in the recesses in the top section, springs inthe recesses in the top section biasing said'bridgin'gcontacts to engage their respective stationary contacts, and plungers reciprocably-mounted in said base section for engagement with'and ac'-' tuation of said bridging contacts, said block and" said plungers providing for each pair of cooperating faces of said contacts a separate insulating chamber,'and said block having conductor passages extending therethrough at points between said chambers.

21. A switch block for drum controllers comprising a block of attenuated form divided longitudinally into a base section and a top section, the top section having therein in alignment longitudinally thereof a series of recesses, pairs of stationary contacts seated in said base section and having extensions extending between theblock sections to the outside of the block and affordingwiring terminals, said pairs of contacts being spaced for locating the same indifferent recesses in the top section and for retention being wedged into sockets in said base section,

bridging contacts movably mounted in the re-' cesses in the top section, springs in the recesses in the top section biasing said bridging contacts to engage their respective stationary contacts and to engage retaining shoulders in said top section from which said contacts may be disengaged by manipulation for removal, and plungers reciprocably mounted in said base section for engage-'7 ment with and actuation of said bridging contacts, said block and said plungers providing for? ing a circuit having an electro'responsive mam switch, in combination, a frame, a shaft rotatably supported thereby, switches mounted on said frame in rows paralleling said shaft, means. including cams on said shaft to operate certain of said switches for commutating connections com pleted through the main switch and to operate other of said switches'to control the main'switch,

the last mentioned switches being in respect of the longitudinal axisof said shaft in a transverse c'o' planar relation to certain of the other of said switches aforementioned. 1 l

23. In a drumtype controller for commutating a circuit having an electroresponsive main switch, in combination, a frame, a shaft rotatably supported thereby, switches mounted on said frame in rows paralleling said shaft, means including cams on said shaft to operate certain of said-switches for commutating connections'completed through the main switch and tooperate] tion to be operated by a cam common thereto,

which cam in the off position of'the'drum effects opening of one of the last mentioned switches and closing of another thereof and upon move ment of the drum from off position to its first on position effects "closure of said openswitch and opening of said switch closed in the off position, meanwhile providing for closure of both of said switches. I 9 24. In a drum type'controller, in combination, a frame, a shaft rotatably supported thereby, switches mounted on said frame, means including cams on said shaft to operate said switches through the medium of said shaft, said shaft whenever operated for circuit change requiring a given degree of reverse movement to perfect the change and a position indicator comprising parts movable relatively upon rotary movement of said shaft to effect a circuit change, one of said parts being fixed to said shaft and another'being stationary' except for a limited play and being coordinated with said shaft to move therewith in either direction between the limits of the aforementioned play.

25. In a drum type controller, in combination, a frame, a shaft rotatably supported thereby, a switch block fixed to said frame in spaced relation to said shaft, a switch in said switch block comprising stationary contacts, and a movable bridging contact, said bridging contact carrying a wear indicating pin extending outwardly of said block, and'operative connections between said shaft and said bridging contact including a cam on said shaft and a plunger operatively associated with said bridging contact and operable by said cam. I

RICHARD B. HUNTER. 1 HAROLD L. MEKELBURG.

REFERENCES CITED The following references are of record in the;

, file ofthispatent-z. v

each pair of cooperating faces of said contactsa separate insulating chamber, and said block sections together with'their respective contactsconstituting self-contained assemblies.

22. In a drum type controllerifor i'com'mutat- 1 UNITED STATES PA'I'ENTS Number" Name Date 1,126,455 Hansen Jan. 26,1915" 1,781,178 Hewlett et al. Nov. 11, 1930 1,794,193 McKerlie Feb. 24, 1931 2,245,369 Smith June 10, 1941 

